This frequency represents not just specific people, but the feeling of normal. It continues even when those people are absent. It defines what you can see and feel in others. If you have no way to receive what they are sending, because you were never exposed to this frequency, then you will have no way of truly understanding them and connecting with them.
It is a truism that if you want to change your life you need to change the people in your life. When this is actually good advice is when you grew up at a dysfunctional frequency, and have surrounded yourself with people who respond to it as well, in the same ways.
And to evolve, to change, to grow, you have at some point to surrender that frequency, to go somewhere else. And what is frightening about this is the lack of givenness. What you grew up with is there even when all the people are gone. When you change frequencies, nobody is there at all. You are in terra incognita.
And obviously, people can be good influences on each other, teachers of one another. One person can gradually teach another to see and feel in a different, better (or for that matter, worse) way.
But I think this is an important point. The specific people come and go, but the memory of what being in that place felt like does not. This is not, by and large, a primarily conscious thing. It goes deep into how “life” feels to us.